Otitis media is a common infectious disease with acute and chronic forms whose developmental and psychoeducational sequelae have not been adequately documented. To examine possible long-term effects of chronic conductive hearing loss during the critical period for normal language learning by the young child, we propose to study longitudinally the development of a hierarchy of behaviors, to examine their interrelationships, and to relate them to the well-documented degree and type of auditory abnormality related to chronic middle ear disease. Two groups totaling 120 "otitis-prone" and control children between 3-5 years at enrollment (half of which have been followed since birth) will be studied. Children's otologic status will be determined from detailed otologic histories and regularly scheduled examinations; audiological status, from regularly scheduled complete evaluations, including auditory brain stem response measurements through 18 months, and impedance measures. Phonetic perception will be tested with natural speech and synthetic speech stimuli. Receptive and expressive speech and language skills will be examined, as will subsequent early reading performance. It will be important to study the way in which these behaviors develop and may interrelate, and how each stage in auditory processing may be manifested in higher-level and more environmentally relevant tasks.